Prosthesis for a lower limb

ABSTRACT

A prosthesis for a residual limb includes an element for receiving a stump fitted on or established by a support part, a distal prosthetic part, and an absorbing system. The distal prosthetic part is assembled on the support part by a pivot link forming a joint to enable flexion or extension of the distal prosthetic part with respect to the element for receiving. The absorbing system absorbs the flexion or extension efforts and is connected to the distal prosthetic part and to one of a rod or a lever that is pivotally fitted on the distal prosthetic device. The rod is mounted to the lever and to the support part.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation application of U.S. patent application Ser. No.14/525,007, filed 27 Oct. 2014, and entitled PROSTHESIS FOR A LOWERLIMB, pending, which is a continuation-in-part of U.S. patentapplication Ser. No. 13/315,827, filed 9 Dec. 2011, and issued 28 Oct.2014 as U.S. Pat. No. 8,870,969, which claims the benefit of FrenchPatent Application No. 1004800, filed 9 Dec. 2010, the entiredisclosures of which are incorporation herein, in their entireties, bythis reference.

BACKGROUND

The present disclosure generally relates to a prosthesis comprising anelement for receiving a stump fitted on or established by a supportpart, a distal prosthetic part assembled on said support part by a pivotlink forming a pivot joint to enable flexion or extension of the distalprosthetic part with respect to the support part, and an absorbingsystem to absorb the flexion or extension efforts.

Persons having a lower limb amputated between the knee and the hip havealready been offered the possibility of being able to ski again.

In a first approach, amputated persons skied on a single leg and wereequipped with crutches provided with small skis at their ends for themto be able to keep their balance.

In a second approach, it was proposed to give amputated persons thepossibility of skiing on two lower limbs with a prosthetic materialperforming functions close to those of a real lower limb underparticular conditions, such as the triple flexion position (hip, knee,ankle) with an absorber enabling the contours of a ski slope to beabsorbed.

Articulated prostheses for the lower limb comprising an element forreceiving a thigh stump of a patient thus exist. The element can then befitted onto a leg by a pivot link the pin of which forms a knee joint toenable flexion or extension of the leg with respect to the element. Ajack enables the flexion or extension efforts to be absorbed.

In the example of FIGS. 1 and 2, a support part 1, on which the elementfor receiving 6 are fitted, is itself fitted on leg 3 by a pivot link 2so as to form a knee joint. Tack 4 is fitted on the one hand on a frontpart of leg 3 (part facing a foot 5), and on the other hand on a rearpart (zone at the level of which the angle a, closes in case of flexion)of support part 1.

FIG. 1 illustrates the position of the prosthesis in flexion with anangle a of 155 degrees between leg 3 and element for receiving 6 at thelevel of the flexion. FIG. 2 illustrates an angle a of 110 degrees. Withangle [alpha] at 155 degrees, the force Fjack exerted by jack 4 is about2500 Newton whereas at 110 degrees the force Fjack exerted by the samejack 4 is about 5100N. The more the prosthesis is flexed, the more thejack will in fact have difficulty in counteracting the flexion, and theuser then finds him/herself without a shock absorbing system which maylead to breaking at the level of the joint. Furthermore, the convenienceof use of the prosthesis is thereby greatly impaired.

SUMMARY

The object of the invention is to provide a more solid prosthesis thathas a behavior close to that of a valid limb, especially for relativelong stumps or patients with a disarticulation.

This object tends to be achieved by the appended claims and inparticular by the fact that the absorbing system is fitted on the onehand on the distal prosthetic part and on the other hand on a leverpivotally fitted on the distal prosthetic device or on a rod, said rodmounted on the one hand on the lever and on the other hand on thesupport part

Such a fitting also results in a compact design and the possibility tolocate the absorbing system at various points, leading to an optimizeddesign and a leverage of the forces acting on the absorbing system.

In one aspect of the invention, the absorbing system comprises at leastone of the following devices: a dampening device, a spring device, andan actuator device. The dampening device may be designed as a hydraulicdamper or as a pneumatic damper or as a combination of hydraulic andpneumatic damper. The spring device may be designed as a single springor a combination of two or more springs. The springs can be designed ascoil springs, helical springs, leaf springs or disk springs as well aselastomer parts. The actuator device may be designed as an electricmotor, a magnetic motor or magnetic actuator, a linear actuator, or ahydraulic motor.

In one aspect of the invention, the support part is a prosthetic shaft,a cup shaped receiving element configured to be connected with aprosthetic shaft or a liner, or an osseointegratable device.

In one aspect of the invention, the lever comprises two lever arms onopposing sides of a pivot axis to establish a rocker, the absorbingsystem being fitted on a first lever arm, and the rod being fitted on asecond lever arm.

In one aspect of the invention, the lever comprises a single lever arm,and the absorbing system is fitted on the lever arm spaced apart from afitting point of the rod on the lever arm.

In one aspect of the invention, the absorbing system or the rod aredisplaceably fitted on the lever.

In one aspect of the invention, the rod, the lever, or the absorbingsystem is variable in its length.

In one aspect of the invention, the distal prosthetic device is hollowwith an inner space in which the lever and the absorbing system are atleast partially arranged.

In one aspect of the invention, the rod covers an opening in the distalprosthetic part at least partially.

In one aspect of the invention, the rod is formed to complete anappearance of a natural limb.

In one aspect of the invention, the joint comprises a joint axis, andthe joint axis runs through the support part.

In one aspect of the invention, the joint comprises a joint axis, andthe joint axis is arranged in an area of a joint axis of a natural limb.

In one aspect of the invention, the joint comprises a joint axis, andthe joint axis is arranged proximal to a distal end of the support part.

In one aspect of the invention, the distal prosthetic part is directlymounted on the support part at at least one bearing point, whereas theat least one bearing point is medially or laterally positioned on thesupport part.

In one aspect of the invention, the at least one bearing point isdisplaceably mounted on the support part.

In one aspect of the invention, the rod is displaceably mounted on thesupport part.

In one aspect of the invention, a locking device is provided to lock theflexion or extension of the joint.

In one aspect of the invention, the lever comprises two lever parts, andthe lever parts are displaceably fitted to each other.

In one aspect of the invention, the lever parts are pivotally fitted toeach other, and the pivot axis of the lever parts aligns with the pivotaxis of the lever.

In one aspect of the invention, the prosthesis is a prosthesis for alower limb, the support part is for receiving a thigh stump or a thighshaft, the pivot link forming a knee joint, and the distal prostheticpart is a shank part. Alternatively, the prosthesis is a prosthesis foran upper limb, wherein the distal prosthetic part replaces the lower armand the pivot link forms an cubital joint. Furthermore, the prosthesismay be designed as a foot prosthesis.

BRIEF DESCRIPTION OF THE DRAWINGS

Other advantages and features will become more clearly apparent from thefollowing description of particular embodiments of the invention, givenfor non-restrictive example purposes and represented in the appendeddrawings in which:

FIGS. 1 and 2 schematically illustrate devices of the prior art indistinct positions.

FIG. 3 schematically illustrates a particular device according to theinvention.

FIG. 4 illustrates a view in three dimensions of the leg and of thesupport part in the flexion position.

FIG. 5 illustrates a view in three dimensions of the leg and of thesupport part in the extension position.

FIG. 6 illustrates a view in three dimensions of the leg and of thesupport part without main body of the leg.

FIG. 7 illustrates a different view of FIG. 6.

FIG. 8 illustrates a view in three dimensions in which the rod isdisengaged.

FIG. 9 illustrates the rod used according to a particular embodiment.

FIG. 10 illustrates a particular embodiment of a lower limb.

FIG. 11 illustrates a scenographic view of a particular embodiment ofthe prosthesis.

FIG. 12 illustrates a lateral view of a prosthesis without absorbingsystem.

FIG. 13 illustrates a sectional view of a prosthesis in extendedposition.

FIG. 14 illustrates a prosthesis according FIG. 13 in 90° flexedposition.

FIG. 15 illustrates a prosthesis according FIG. 13 in maximal flexedposition.

FIG. 16 illustrates dampening characteristics over a knee angledepending on the length of a damper.

FIGS. 17 to 24 illustrate schematic views of different embodiments ofthe invention.

FIGS. 25 to 27 illustrate schematic view of multi-part rockers.

DETAILED DESCRIPTION

The prosthesis described in the following differs from the prosthesisaccording to the prior art in that its particular assembly enables theefforts of the absorbing system to be limited.

What is meant by lower limb of a person is a thigh, a knee and a foot.The thigh is the part situated between the hip and the knee, and the legis the part situated between the knee and the instep.

FIG. 3 schematically illustrates a prosthesis for a lower limbcomprising element for receiving 6 a thigh stump fitted on a supportpart 1. A leg 3 is assembled on said support part 1 by means of a pivotlink 2 forming a knee joint to enable flexion or extension of leg 3 withrespect to the element for receiving 6 (at angle [alpha], in FIG. 3). Aabsorbing system 4, enabling the flexion or extension efforts to beabsorbed, is fitted on the one hand on the pin of pivot link 2 and onthe other hand on a first end of a rocker 7 pivotally mounted on leg 3.A rod 8 is fitted on the one hand on a second end of rocker 7 and on theother hand on support part 1 so as to transmit the pivoting movement ofthe support part around the pin of pivot link 2 to the rocker to solicitthe absorbing system more or less.

When support part 1 pivots around the pin of pivot link 2, rod 8transmits the pivoting to the rocker, thereby transmitting the movementto the absorbing system 4 decreasing, or increasing, the distanceseparating the assembly point of absorbing system on rocker 7 from theassembly point at the level of the pin (also called “axis” in thedomain) of pivot link 2. In other words, the smaller the angle a is, themore the absorbing system will be compressed, i.e. in case of flexion,the distance separating the assembly point of said system 4 on therocker will move towards the pin of pivot link 2. Naturally, therespective assembly points of absorbing system 4 and of rod 8 at thelevel of the rocker are advantageously situated at the ends of rocker 7arranged on each side of swivel pin 9 of rocker 7. Furthermore, in theparticular implementation, the assembly point of rod 8 at the level ofsupport part 1 is situated on the same side as the assembly point of rod8 on rocker 7.

In other words, rocker 7 can comprise two branches 7 a, 7 b on each sideof its swivel pin 9. A first branch 7 a is directed towards a firstsurface called front surface of the prosthesis (the front surface is infact the surface of the prosthesis facing a foot 5). A second branch 7 bis directed towards a second surface, opposite the first surface, andcalled rear surface of the prosthesis (the rear surface of theprosthesis corresponds to the rear face of a lower limb, i.e. the facewhich will enable element for receiving 6 to be moved towards leg 3 byflexion). In the particular example of FIG. 3, absorbing system 4 isfitted on first branch 7 a of rocker 7 at an end of first branch 7 aproximal to the front surface of the prosthesis. Rod 8 is fitted onsecond branch 7 b of rocker 7, at an end of rocker 7 proximal to therear surface of the prosthesis, and fitting of rod 8 at the level ofsupport part 1 is performed at the level of the rear surface of theprosthesis.

FIGS. 4 and 5 illustrate a particular embodiment. According to thisparticular embodiment, leg 3 can have a monoblock main part comprising abase 3 a connecting two uprights 3 b, 3 c substantially parallel to oneanother.

At the end of leg 3 distal from base 3 a, a pin can be fitted so as toconnect the two uprights 3 a, 3 b, preferably perpendicularly. This pincan be fixed with respect to uprights 3 b, 3 c. Support part 1 ispivotally mounted on this pin, designed to form pivot link 2 referred toin the foregoing.

Support part 1 can be a part which is for example monoblock, comprisinga first assembly zone designed to receive the pin of pivot link 2 and asecond assembly zone designed to receive a pin for fixing one end of rod8. As illustrated in FIG. 6 in which the main body of leg 3 has beenremoved for the sake of clarity, the first assembly zone can comprisetwo sections 10 a, 10 b each comprising a bore, the bores of saidsections 10 a, 10 b being coaxial. The two sections 10 a, 10 b areseparated by an empty space, between the two sections 10 a, 10 b,designed to receive one end of absorbing system 4 equipped with a firstassembly part 11 a comprising a bore designed to receive the pin ofpivot link 2. Thus, in the assembled position, the pin of pivot link 2passes through the two bores of sections 10 a, 10 b of support part 1,and the bore of first assembly part 11 a.

In FIGS. 4 and 5, the pin of pivot link 2 of the joint is fixed at thelevel of the two uprights 3 b, 3 c of leg 3, and support part 1 andabsorbing system 4 are mounted with swiveling/rotation on the pin ofpivot link 2 between the two uprights 3 b, 3 c.

Rocker 7 can be secured to said to uprights 3 b, 3 c by swivel pin 9between the two uprights 3 b, 3 c, and preferably in proximal manner tobase 3 a, (FIGS. 4 to 6). Rocker 7 then comprises two distal ends formedby branches 7 a, 7 b visible in FIG. 7, a first end being directedtowards the front part of leg 3 and a second end being directed towardsthe rear part of leg 3. The first end is designed for fitting ofabsorbing system 4. Absorbing system 4 can be fitted on this first endby means of an associated pivot link. In the particular example of FIG.6, at its first end, the rocker comprises two sections of rocker 12 a,12 b separated by an empty space, forming a Y. Between the two sectionsof rocker 12 a, 12 b, a second assembly part 11 b(FIG. 6) of absorbingsystem 4 is inserted in such a way that a common pin can be inserted inthe bores respectively formed at the level of the two sections 12 a, 12b of rocker and of second assembly part 11 b.

The second end of rocker 7 is designed for fitting of rod 8. Rod 8 canbe fitted on this second end by means of a pin forming a pivot link. Inother words, at its second end, the rocker can comprise a bore receivinga pin on which rod 8 can be fitted.

Opposite its fitting point on rocker 7, rod 8 can be mounted pivotingaround a pin arranged at the rear (rear surface of the prosthesis) ofsupport part 1, said pin being able to be fixed with respect to supportpart 1. In FIGS. 4 and 5, rod 8 can comprise two distal ends in the formof a Y so as to respectively receive a part of rocker 7 and a part ofsupport part 1 in the space separating the two branches of the Y,thereby enabling assembly to be performed by means of correspondingpins. The parts of the rocker and of support part 1 each comprise a boredesigned to receive a pin forming an assembly point of rod 8.

In the particular example of FIGS. 4 and 5, for rod 8, the pin at thelevel of the rocker is fixed with respect to rod 8, enabling swivelingof the rocker around this pin. The pin at the level of support part 1 isfixed with respect to support part 1, enabling swiveling of rod 8 aroundthis pin. For the absorbing system, it is fitted swiveling on the pin ofpivot link 2 and on the pin acting as assembly point on the rocker, saidassembly pin being fixed with respect to it) the rocker.

According to a particular embodiment, rod 8 can be arranged so as tooccupy a first position in which the swiveling movement of support part1 with respect to leg 3 is transmitted to rocker 7, and a secondposition (FIG. 8) in which said movement is not transmitted to rocker 7(FIGS. 4 and 5). This can for example be achieved by a rod 8, asillustrated in FIG. 9, comprising a first plate 12 a (or element)mounted on support part 1 (FIGS. 4 to 8) and a second plate 12 b (orelement) mounted on rocker 7. First plate 12 a forms a hinge 13 withsecond plate 12 b. In other words, first plate 12 a is pivotally mountedon second plate 12 b to prevent transmission of a movement of supportpart I to rocker 7, should such a movement take place. Hinge 13 can beformed on the median of rod 8, perpendicularly to the longitudinal axisA1 of said rod 8.

This rod 8 with two positions presents an advantage when the prosthesisis used for skiing. In a first position, the skier can in fact solicitthe prosthesis when descending a slope, and when he/she embarks on a skilift, the prosthesis can move to the second position of rod 8 enablingthe skier to sit down without difficulty on the seat of the ski lift asthe absorbing system 4 is deactivated.

Rod 8 preferably comprises latching means arranged so as to preventswiveling of first plate 12 a with respect to second plate 12 b in thefirst position and to enable said swiveling in the second position.

FIGS. 5 to 9 illustrate a particular embodiment of such latching means.The latter can comprise a mounting plate 14 fitting sliding on one ofplates 12 a, 12 b, preferably on the rear surface of the prosthesis, ina plane parallel to the plane of the associated plate. At one end,mounting plate 14 preferably comprises first engagement means 15 acollaborating in the first position with second engagement means 15 b ofthe other plate to latch the first and second plates to one another. Inthe first position, the first and second plates are deprived of relativemovements with respect to one another. In other words, the two platesbehave as a monoblock part. In the second position, first plate 12 a canswivel with respect to second plate 12 b, for example at the level ofhinge 13, so as not to transmit the movement from support part 1 torocker 7, this enabling the stresses imposed on absorbing system 4 to berelaxed.

In a particular example of FIGS. 4 to 9, mounting plate 14 comprises abase 14 a joining two parallel opposite sides walls 14 b, 14 c, orientedin the longitudinal direction (axis A1 in FIGS. 7 and 9) of rod 8 in thefirst position. A transverse dimension of base 14 a is larger than thetransverse dimension of first plate 12 a so that base 14 a snuglyfollows a main surface 16 of said first plate 12 a. In the example, mainsurface 16 is substantially parallel to the plane of first plate 12 a.The two opposite sides walls 14 b, 14 c each respectively snugly followan edge 17 of the first plate 12 a (edge substantially perpendicular tosurface face 16). Edges 17 of first plate 12 a each comprise at leastone protrusion 18 substantially perpendicular to said edge 17. Eachprotrusion 18 collaborates with an aperture 19 made in correspondingside wall 14 b, 14 c of mounting plate 14. According to the particularembodiment, each edge 17 comprises two protrusions and each side wallcomprises two corresponding apertures. The apertures and protrusions onthe one hand enable the mounting plate to be kept mounted on first plate12 a, and on the other hand enable the travel of mounting plate 14 to belimited with respect to first plate 12 a. In other words, a protrusionpasses at least partially through the associated aperture to form a stopfor movement of mounting plate 14 with respect to the first plate. Thetransverse dimensions of the protrusion are substantially equal to thetransverse dimensions of the aperture perpendicularly to thelongitudinal axis of the side walls.

In order to block first plate 12 a with second plate 12 b, mountingplate 14 can comprise two recesses 20 a, 20 b forming the firstengagement means, at an end directed towards second plate 12 b (FIG. 8),each recess being made at the level of a side wall of mounting plate 14and running along the longitudinal axis of mounting plate 14. In thefirst position, each recess 20 a, 20 b collaborates with a correspondinglug 21 of second plate 12 b which is then housed in the associatedrecess. Lug 21, forming the second engagement means, is formed salientfrom an edge of second plate 12 b.

Mounting plate 14 is preferably constantly biased in the direction ofthe plate on which it is not fitted, for example by biasing element suchas a spring.

This embodiment can be implemented as for example in FIG. 9 in whichfirst plate 12 a comprises a through opening 22 made at the level of oneof its surfaces perpendicularly to the plane of said first plate 12 a.The base of the mounting plate then comprises a protuberance 23 able tomove in opening 22, between the two sides walls 14 b, 14 c, saidprotuberance 23 then being connected to an inner surface of the openingby a spring 24 so as to stress movement of mounting plate 14 in anopposite direction to the first element (in the direction of arrow F1 inFIG. 8). In FIG. 8, spring 24 is a compression spring and the latterconnects protuberance 23 to a distal inner surface of the opening ofhinge 13. The person skilled in the art can naturally also use a tensionspring secured to the protuberance and to an inner face of the proximalopening of hinge 13.

The user of the prosthesis can thus pull on the mounting plate in anopposite direction to arrow F1 to disengage the recesses from theirrespective lugs and to move the prosthesis to the second position of rod8. To be able to return to the first position, the user can perform thereverse action. In preferential manner, the ends of side walls 14 b, 14c of mounting plate 14 at the level of the recesses and facing theassociated lugs each comprise a bevel enabling automatic latching of therecesses with the lugs when the user resumes a standing position. Rod 8tends to return to the first position, when returning on the feet upposition, and the bevel then comes into contact with an associated lug,naturally pushing mounting plate 14 in an opposite direction to arrow F1until engagement is achieved. In other words, in general manner, thefirst and second engagement means can be formed in such a way as toengage automatically when extension of the prosthesis takes place whenthe latter is in the second position.

This involves an example embodiment, the person skilled in the artnaturally being able to modify the assembly, for example by reversingassembly of the first plate and of the second plate respectively on therocker and on the support part.

According to a development, the absorbing system comprises a jack. Thejack is preferably of oleo-pneumatic type. It preferably enablesdistinct adjustment of its compression force and of its speed ofexpansion. In other words, the jack can comprise distinct means foradjusting its compression force and its speed of expansion. For example,the speed of expansion can be adjusted to provide a softer return fromthe flexion position to the extension position. This enables, inparticular, the lower limb to be adjusted according to the level and thedesire of the user.

By extension, when referring to a lower limb prosthesis, the element forreceiving a thigh stump, the support part and the leg are mechanicalelements enabling an amputated person, for example a skier, to find hisbearings on both of his lower limbs, and to perform functions close tothat of a real lower limb under particular conditions such as the tripleflexion position (hip, knee, ankle). For this, the pins referred toabove (pivot link pin, assembly pins of the rod on the support part andon the rocker, assembly pin of the absorbing system on the rocker andswivel pin of the rocker), are all preferably substantially parallel toone another.

As illustrated in FIG. 10, the prosthesis can further comprise a foot 25fitted on one end of leg 3 opposite support part 1, for example on a rod26 of the leg fixed to the main body 3 a, 3 b, 3 c opposite the supportpart. Foot 25 is pivotally mounted on said leg 3, the axis of pivotingthen being substantially parallel to the pin of pivot link 2 forming thejoint. Rod 26 can be assembled on foot 25 by a pin 27 at the level ofthe area called the instep. Rod 26 can be connected by means of a jack28 with one end of foot 25 opposite rod 26.

The use of jack 28 at the level of the foot enables a compensation ofthe flexion of the prosthesis to be obtained at the level of the jointby a dorsal flexion of the foot.

According to an alternative embodiment (not shown), a sole is fitted ona bottom surface of the foot, said sole taking a shape designed tocollaborate with a binding for a ski boot.

In the particular case of snow sports, the amplitude of movementprovided by such a prosthesis enables the user to adapt to any type ofskiing or snow surfing.

Support part 1 can comprise a preferably flat surface opposite the joint(pivot link 2) designed for fixing element for receiving 6 a thighstump. These element for receiving can comprise a plate, for examplefixed to said surface by screws. The plate of the element for receivingis itself fixed to a receptacle, for example made from carbon fiber,shaped in the same way as the stump of the user's lower limb.

Tests carried out on this prosthesis using a jack as absorbing systemhave enabled it to be shown that, with an angle of flexion a of 155degrees, the force exerted by the jack is about 2200N Newton, whereaswith an angle of flexion a of 110 degrees, the force F_(jack) exerted bythe jack of the absorbing system is about 3340N. In other words,compared with the prior art, the prosthesis described above enables asubstantially constant absorbing force to be kept on the jack whateverthe angle of flexion at the knee, in particular due to the use of arestoring force. Thus, unlike the prior art, this prevents absorbingfrom being lost and procures an improved user comfort approaching thatof a valid lower limb.

Apart from the fact that the prosthesis is more robust, keeping asubstantially constant force at the level of the absorbing systemwhatever the angle of flexion a of the prosthesis enables enhancedperformances to be achieved throughout a ski run. This in particularmakes it possible to press on the prosthesis while at the same timekeeping a high level of control of the ski even when pressing isunilateral.

FIG. 11 illustrates an alternative embodiment of an above kneeprosthesis comprising a support part 1, fitted to receive a stump or formounting a receiving element, which is designed to receive a thighstump, especially a stump with a disarticulated shank. The receivingelement or the support part can be a prosthetic shaft for encircling thestump, lateral rails or splint with belts and hook and loop fastenersfor fitting the receiving element to the stump, or as a support part foran osseointegratable implant device. The osseointegratable implantdevice can be established by or fixed at the support part. The supportpart 1 can receive the stump directly or with a liner, fixed to thesupport part by a pin or low pressure. If the receiving element isdifferent to the support part, it can be fitted onto the support part bylateral lugs or brackets 110, 120. The lugs or brackets 110, 120 arefixed at the support part 1, the receiving element can be fixed to thelugs or brackets 110, 120 by screws, bolts or other positive lockingmeans. The receiving element can also be fixed on the cup shaped supportpart 1 by gluing, welding or form fitting elements like a shuttle lockor a pin or by magnetic holders.

A distal prosthetic part 3 in form of a prosthetic shank is assembled onthe support part 1 by a pivot link, forming a pivot joint 2 so that thedistal prosthetic part 3 can be pivoted around a joint axis 150 forflexion or extension of the distal prosthetic part. The joint axis 150is orientated in medial-lateral direction, preferably through the lugsor brackets 110, 120. Bearing points 71, 72 are provided on medial andlateral parts of the support part 1 and distal prosthetic part 3, sothat a pivot link 2 or a pivot joint 2 is established. The distalprosthetic part 3 is hollow and comprises an inner space 250.

An absorbing system 4 is arranged inside the inner space 250. Theabsorbing system can comprise at least a dampening device, a springarrangement and/or an actuator device. In the shown embodiment, theabsorbing system 4 is a hydraulic dampening device with a proximalfixing or bearing point that is positioned distal to the support part 1.The proximal bearing point enables a swiveling movement of the dampeningdevice 30 around an axis 31 that is orientated parallel to the jointaxis 150.

On a rear, posterior part of the support part 1, a protrusion 130 ispositioned for receiving and supporting a rod 8. The rod 8 is positionedposterior to the joint axis 150 and can swivel around an axis 114. Axis114 is spaced apart from the joint axis 150 so that upon rotation of thesupport part 1 around the joint axis 150 the upper part of the rod 8performs an orbital movement. Therefore, the rod 8 performs a movementin a vertical and a horizontal direction.

FIG. 12 illustrates a lateral view of a prosthesis without the posteriorrod 40. The proximal axis 31 of the absorbing system 4 as well as adistal rotation axis 51 of a lever (not shown in FIG. 12) can be seen.The position of both axes 31, 51 can be altered in or on the distalprosthetic device 3, so that the distance and orientation of the axes31, 51 can be adjusted and fixed in the adjusted position.

In FIG. 13 a sectional view of the prosthesis is shown. The cup shapedsupport part 1 can receive a thigh stump, a shank stump or an upper arm.The protrusion 130 is positioned at the posterior part of the supportpart and fitted to receive a pin or stud to form a bearing point 140 fora pivotal support of the rod 8. Rod 8 is connected with its proximalarea, more precisely with the proximal end 41 at the bearing point 140with the support part. The opposing, distal end of the rod 8 issupported on a lever 50. Lever 50 is pivotally supported at the distalprosthetic part 3. Lever 50 has two arms, one on each side of a pivotaxis 51 and establishes a rocker. Rod 8 forms with lever 50 a bearingpoint 160, so that the lever 50 will be pivoted when the rod 8 isactuated by flexion or extension of the support part 1 around the jointaxis 150.

On the opposing lever arm, i.e. the lever arm on the other side of thepivot axis 51, the distal or lower end of the absorbing system 30 ismounted in a lower bearing point 320. The lever 50 itself is mountedpivotally inside the hollow inner space 250 of the distal prostheticpart 250 at the bearing point 510. Bearing point 320 enables a swivelingmovement between the piston rod 35 and the lever 50 so that the pistonrod 35 can perform a linear movement if the lever 50 swivels around thepivot axis 51. This leads to a linear movement of the piston 34, whichis coupled with the piston rod 35 inside the hydraulic cylinder 33. Theupper end of the absorbing system 4 is pivotally mounted at the upperbearing point 30 thereby forming an axis 31 of rotation.

In the shown embodiment of FIG. 13, the bearing points 140, 160, 310,320, 510 of the components are set. In an alternative embodiment thebearing points 140, 160, 310, 320, 510 are adjustable, either steplesslyor stepwise adjustable, so that the respective components can bearranged in different orientations, locations and distances to eachother to adapt the arrangement to requested requirements. By changingthe distances between the bearing point 160, 320 of the rod 8 and theabsorbing system 4 on the lever 50, the leverage ratio of the rocker canbe altered so that the travel of the piston 34 and the piston deadcenter is adjustable. Furthermore, rods 40 of different lengths orlength adjustable rods can be used, such as, for example, telescopicrods, rods with threaded sleeves, or rods with adapters. By this it ispossible to change the characteristics of the adsorbing system, thepiston dead center of a hydraulic damper, and the force ratios.

FIG. 14 shows the prosthesis in a flexed position in which the supportpart 1 is flexed about 90° relative to the distal prosthetic part 3compared with the maximum extended position shown in FIG. 11. Because ofthe orbital path of the upper bearing point 140 of the rod 8, the rod 8is swiveled relatively to the support part 1 and is moved in an anteriordirection as well as in a distal direction, causing a counterclockwiseswiveling movement of the lever 50 around pivot axis 51. This causes anupwardly directed movement of the other lever arm and the bearing point320 of the piston rod 35 in the direction of the upper bearing point310. By this, the piston 34 is moved inside the cylinder 33.

FIG. 15 shows the prosthesis in its maximal flexed position. Supportpart 1 is swiveled around the joint axis 150 so that a receiving element6 (shown in dotted lines) contacts the rear or posterior part of thedistal prosthesis part 3. Rod 8 is moved back into a distal directionbecause the upper bearing point 140 is moved after reaching its mostdistal point of motion in an upward direction so that the lever isrotated in a clockwise direction coming from the position shown in FIG.14. This leads to a reversal of movement of the piston 34 in thecylinder 33. With different resistances in the damper for upward anddownward movement by choosing different valves or throttles it ispossible to provide the damper with different resistances according tothe direction of movement. From a maximal extended position as shown inFIG. 13 to the 90° flexed position according to FIG. 14, the pistonmoves upwardly up to its uppermost position. When flexing the supportpart further into the position of FIG. 15 or if the support part ismoved back in an extension direction, the piston 34 reverses itsmovement and can provide a lesser resistance than in the otherdirection.

As already mentioned the absorbing system 4 can be equipped with atleast one of the group consisting of a damper, a spring or an actuator(e.g., a motor, electro magnet or the like). Such absorbing system isarranged at least partially inside the hollow inner space 250 of thedistal prosthetic device, which is formed like a tube with an outerappearance of the limb to be replaced. The lever 50, as well as thepiston rod 35 and the rod 8, can be variable in their length, forexample by threaded sleeves. A variation of the length can be providedby a number of mounting points on the lever 50 or rod 8.

Besides an adjustment of the bearing points 140, 160, 320, it ispossible to adjust the bearing points of the lever 50 and the absorbingsystem 4 in or on the distal prosthetic device 3. In other words, it ispossible to position the bearing points 140, 160, 320 at different spotsor places on the prosthetic device 3 and to fix them at the respectivespots. The static and dynamic set up of the prosthesis is changed by thearrangement of the bearing points 310, 520.

The AKP (above knee prosthesis) according to the embodiments of FIG. 11to FIG. 15 is especially suited for patients with a kneedisarticulation, since the stump can protrude in the clear space of thecup shaped support part 1 so that the joint axis 150 of the pivot link 2can be located in the position of the natural joint of the sound leg.The position of the joint axis 150 can be individually chosen by placingthe bearing points 71, 72 at the support part 1 or at the receivingdevice 6. The distal prosthetic device 3 has at its upper ends medialand lateral flanges which are arranged left and right to the supportpart 1 and establish corresponding bearing points. Since AKP for kneedisarticulated patients cannot be adjusted in their proximal set up bypyramidal adapter, the bearing points may be adjustable. Furthermore,the lever 50 can be designed as a multipart lever with at least twolever parts or lever branches, which can be rotated relative to eachother about an axis to change the angle between the lever parts. Bychanging the angle, the distance between the bearing points 160, 320 canbe altered as well as the distance between the lever parts and thebearing points 140, 310 of the rod 8 and the absorbing system on the leg3. The axis of the multipart lever is preferably parallel or identicalwith the swivel axis 51 of the lever 50. By alternation of the anglebetween the lever parts is it possible to change the position of thereversal point or piston dead center point and to alter the dampercharacteristics or actuation characteristics of the absorbing system 4.

FIG. 16 shows some diagrams of a damping force over the knee angledepending on different length of the hydraulic damper 4 and the rod 8.The uppermost graph in the upper diagram depicts the dampening forcewith a long rod 8, the middle graph is for a little shorter rod, and thethird graph shows the dampening force with a shortest rod. Depending onthe length of the rod and the dampening device the piston dead center isreached at different knee angles. As the rod is lengthened, the pistonreaches dead center sooner, which means that the lowest dampening isreached earlier compared with shorter rods. This is because thedampening force decreases in the area of the piston dead center. It isadvantageous that the dead center point is located in the area of about90° flexion, which is an angle normally present when sitting.

The lower diagram shows the dampening characteristics for differentpositions of the bearing points and length of the rod and the absorbingsystem. It can depicted from this diagram that it is possible to adjustthe dampening characteristics by amending the geometric positions andorientations of the components of the prosthesis.

By amending the length of the lever or lever branches and the positionof the piston rod or the absorbing system it is possible to adjust anextension stop of the prosthesis. This can be reached by adjusting theabsorbing system, e.g. by adjusting the length of the piston rod or byadjusting the length of the rod 8. Furthermore, it is possible to designthe lever or rocker 50 as a two-part lever with two branches which canbe pivoted or rotated relative to each other so that by amending theorientation of the lever arms or branches it is possible to adjust theposition and the relative length of the rod and the absorbing system.

The dampening characteristics of the absorbing system 30 are previouslyadjusted in accordance to the joint angle (e.g., especially a kneeangle) so that the dampening characteristics are optimized for theintended purpose of the prosthesis.

FIG. 17 schematically illustrates the arrangement of the componentsaccording to FIGS. 13 to 15. The pivot joint axis 150 is positionedproximally to the distal end of the support part 1 so that an adjustmentor correction of the length of a prosthetic shaft can be carried outeasily since the bearing points 71, 72 of the pivot link 70 can belocated almost freely along the longitudinal direction of the supportpart 1. It is possible to arrange the pivot axis 150 in an area of anatural joint axis so that it is possible to provide a patient withalmost equal along limb parts so that a more natural movement can becarried out with a prosthesis according to the claimed invention.Besides an embodiment as shown for patients with a knee disarticulationit is possible to fit such prosthesis on a shank stump or an upper armstump. The lever 15 according to this embodiment is designed as a rockerwith two lever branches 52, 53, the rod 8 is arranged at the rear leverbranch 53, and the absorbing system 3 is arranged on the opposite leverbranch 52. The lever 15 or rocker is pivotally supported and can bepivoted around the swivel axis 51. The bearing points 160, 320 of theabsorbing system 3 and the rod 8 can be adjusted as well as the bearingpoint of the rocker 50.

FIG. 18 schematically illustrated an alternative embodiment comprising asingle arm lever 50 on which the bearing points 320, 160 of theabsorbing system 4 and the rod 8 are located on the same side of theswivel axis 51. The bearing points 160, 320 are spaced apart from eachother and can be located at different positions on the lever 50. Byadjusting the distance between the bearing points 160, 320 and theposition of the bearing parts 160, 320 is it possible to change theforce ratio as well as the path ratio. The upper bearing point 310 ofthe absorbing system 4 is arranged above at a proximal point compared tothe swivel axis 51.

A further alternative embodiment is shown in FIG. 19. The differencebetween FIG. 18 and FIG. 19 is that in FIG. 19 the bearing point 310 ofthe absorbing system 4 on the leg 3 or distal prosthetic part 3 isdistal to the bearing point 510 of the lever 50. Such an arrangement isadvantageous if the swivel axis 51 has to be positioned very near to thesupport part 1 so that no room is left for positioning the absorbingsystem 4. As in the previous embodiments, the bearing points 510, 320,310 and 160 can be relocatable on the lever 50 or at the distalprosthetic part 3.

A further embodiment is shown in FIG. 20 with a bearing point 510 of thelever 50 in the middle or posterior part of the distal prosthetic part3. The bearing point 310 of the absorbing system 4 is arranged distallyto the bearing point 510 and in the posterior part of the leg 3. Rod 8when in an extended position is positioned outside of the inner space 25of the low leg 3.

FIG. 21 illustrates a further embodiment with a rod 8 crossing absorbingsystem 4. With such an arrangement having a single arm lever 50 with itsbearing point 510 at the distal prosthetic part 3 it is possible tointroduce a rod 8 in the inner space 25 near the upper end so that it isprotected by the prosthetic part 3. By rotating the support part 1around the pivot axis 150, lever 50 turns counterclockwise so that theabsorbing system is under tensile load. By reversing the movement of therod 8, the absorbing system 4 is under compressive load.

FIG. 25 illustrates a further embodiment of the claimed invention inwhich bearing point 510 of single arm lever 50 is located posterior tothe joint axis 15, lever arm protrudes in an anterior direction androtates counterclockwise when support part 1 is rotated clockwise forflexion. This embodiments enables a positive path ratio for theabsorbing system 4 which means that the distance between the upperbearing point of the rod 8 and the joint axis 51 can be comparativelysmall. The double arrows indicate the possible adjustment path along thelongitudinal direction of lever 50.

A further embodiment is shown in FIG. 23, in which the absorbing systemis not fixed to the lever 50 but to the rod 8 in its distal part 42.Lever 50, with its bearing point 510 proximal to the bearing point 310of the absorbing system 4 on the leg 3, provides guidance of the rod 8and absorbing system 4. The bearing point 320 can be moved along the rod8. A gear ratio regarding force and path is established because of thespecific orientation of the angles of the rod 8 and the longitudinaldirection of the absorbing system 4.

FIG. 24 illustrates a variation of FIG. 23 with the absorbing system 4providing recourse to dampening devices like hydraulic or pneumaticdampers. It is understood that the absorbing system can compare or beestablished by spring devices and/or actuators as well.

Especially FIGS. 11 to 15 show that rod 8 is guided into the inner space250 of the distal prosthetic part 20. A distal prosthetic part 20 has atube-like form with an outer appearance similar to a natural limb (e.g.,the embodiment of FIGS. 11 to 15 in the form of a shank). A distalprosthetic part 3 is provided with a cutout 260 which is at least partlycovered by a rod 8. Rod 8 completes the outer contour of the distalprosthetic part 3. Furthermore, the cutout 260 enables the support part1 and the receiving element 6 to conduct a flexion movement greater than90°. Such a position is shown in FIG. 15. Rod 8 is located posterior tothe pivot axis 150 and in front of the cutout 260 and acts like a coverfor the absorbing system 4 and the lever mechanics. Furthermore, it is acontour completing part of the prosthesis.

Absorbing system 4 can be a damper alone or a combination of a damperwith a spring unit and/or an actuator unit which can be established as amotor and can provide a driving or decelerating effect of the prostheticjoint. The absorbing system can be controlled mechanically withoutelectronic devices. In the alternative, it is possible to provide acontrol with an angle sensor and a torque sensor more precisely with aknee angle sensor and torque sensor for determining the torque had anankle joint. Furthermore it is possible to provide a control by aninertial sensor arranged in the distal prosthetic part 3 in combinationwith a hydraulic dampening system which locks the joint if a load isexerted. Furthermore, a combination with an inertial sensor in thedistal prosthetic part 3 in combination with a torque sensor in thepivot joint 2 can be used together with a force sensor for determining aforce acting along the piston rod or on the bearing points 310, 320 ofthe absorbing system. Furthermore, such a force can be determined bymeasuring the pressure in the hydraulic circuit of a dampening system.

Inertial sensors can be provided in the support part 1, in the receivingelement 6, as well as in the distal prosthetic part 3. Inertial sensorscan be established by a gyroscope as well as acceleration sensors andcombinations of both sensor types. Force sensors can be established bystrain gauges, pressure sensors can be established by piezo elements,and angle sensors can be established by Hall-effect sensors.

By providing the prosthesis with a rod in combination with a lever it ispossible to significantly reduce the stroke of travel of piston in thedamper or the actuator. A reduction of the stroke or travel of a pistonleads to a reduction of the length of the cylinder or housing so thatthe absorbing system 3 can be shortened by the double of the reductionof the stroke or travel. This is of great importance in prostheticdevices with restricted installation space.

By amending the length of the rod 8 as well as by extending orshortening the absorbing system or adjusting the angular position of thelever branches it is possible to amend and adjust the position andorientation of the support part 1 and by this of the receiving element60 and the set-up of the complete prosthesis. The support part 1 can becup-shaped so that it is possible to support a stump directly, ifnecessary with advanced prosthetic shaft concepts. Since the pivot axis150 is located on the support part 1 proximal to the distal end of thesupport part 1 it is possible to locate the joint axis 150 along thelongitudinal direction of the stump, receiving element 6, or supportpart 1. By this it is possible to locate the pivot axis in the area of anatural joint as well as proximal on the support part 1 or receivingelement 6. By locating the pivot axis 150 proximal as much as possible,the moment of inertia of the distal prosthetic part 3 is reduced so thatthe patient is provided with a subjective lighter prosthesis.

FIG. 25 illustrates an embodiment of a two-part-lever 50 comprising afirst lever branch 52 and a second lever branch 53 which are pivotallyconnected and can rotate around a common swivel axis 51. Each of thelever branches 52, 53 is provided with a side arm 56, 57. Threads areprovided in the side arms 56, 57 in which screws 54, 55 are arranged.Screws 54, 55 are adjustment screws, wherein one of the screws acts to atensioning element to pull the side arms 56, 57 to each other whereasthe other screw acts as a fixing device and acts against the first screwso that the side arms 56, 57 are braced against each other. In theposition according FIG. 25, the respective bearing points 160, 320 arein their maximal distance and the lever branches 52, 53 form a straightrocker.

FIG. 26 illustrates the lever 50 of rocker 50 in a pivoted position, andthe tension screw 54 is driven in the side arms 56, 57 so that the sidearm 56, 57 are moved towards each other which leads to a rotation of thelever branches 52, 53. This in turn leads to an adjustment of theposition of the bearing points 160, 320. The distance between thebearing points 160, 320 is reduced, the position of the rod (not shown)relative to the absorbing system (not shown) is adjustedcorrespondingly.

FIG. 27 illustrates a further embodiment of the lever 50, whereininstead of screws 54, 55 several bores or drilled holes 58 are arrangedcircularly around the swivel axis 51. The bores or drilled holes 58 areprovided in both lever branches 52, 53. With a form-fitting element, forexample a bolt or a pin, the orientation of the respective bores ordrilled holes can be fixed after alternation and the position of thebearing points 160, 320 can be adjusted in the required position byamending the angular position of the lever branches 52, 53.

What is claimed is:
 1. A prosthesis for a residual limb, comprising: anelement for receiving a stump fitted on or established by a supportpart; a distal prosthetic part assembled on said support part by a pivotlink forming a joint to enable flexion or extension of the distalprosthetic part with respect to the element for receiving; an absorbingsystem to absorb the flexion or extension efforts, said absorbing systembeing connected to the distal prosthetic part and to one of a rod or alever that is pivotally fitted on the distal prosthetic device; whereinthe rod is mounted to the lever and to the support part.
 2. Theprosthesis according to claim 1, wherein the absorbing system comprisesat least one of a dampening device, a spring device and an actuatordevice.
 3. The prosthesis according to claim 1, wherein the support partcomprises one of a prosthetic shaft, a cup shaped receiving elementconfigured to be connected with a prosthetic shaft or a liner, or anosseointegratable device.
 4. The prosthesis according to claim 1,wherein the lever comprises two lever arms on opposing sides of a pivotaxis to establish a rocker, the absorbing system being fitted on a firstlever arm, and the rod being fitted on a second lever arm.
 5. Theprosthesis according to claim 1, wherein the lever comprises a singlelever arm, the absorbing system being fitted on the lever arm spacedapart from a fitting point of the rod on the lever arm.
 6. Theprosthesis according to claim 1, wherein the absorbing system or the rodare displaceably fitted on the lever.
 7. The prosthesis according toclaim 1, wherein at least one of the rod, the lever, and the absorbingsystem has a variable length.
 8. The prosthesis according to claim 1,wherein the distal prosthetic device is hollow with an inner space inwhich the lever and the absorbing system are at least partiallyarranged.
 9. The prosthesis according to claim 1, wherein the rod atleast partially covers an opening in the distal prosthetic device. 10.The prosthesis according to claim 9, wherein the rod is formed tocomplete an appearance of a natural limb.
 11. The prosthesis accordingto claim 1, wherein the joint comprises a joint axis, and the joint axisruns through the support part.
 12. The prosthesis according to claim 1,wherein the joint comprises a joint axis, and the joint axis is arrangedin an area of a joint axis of a natural limb.
 13. The prosthesisaccording to claim 1, wherein the joint comprises a joint axis, and thejoint axis is arranged proximal to a distal end of the support part. 14.The prosthesis according to claim 1, wherein the distal prosthetic partis directly mounted on the support part at at least one bearing point,and the at least one bearing point is medially or laterally positionedon the support part.
 15. Prosthesis according to claim 14, wherein theat least one bearing point is displaceably mounted on the support part.16. The prosthesis according to claim 1, wherein the rod is displaceablymounted on the support part.
 17. The prosthesis according to claim 1,further comprising a locking device configured to lock the flexion orextension of the distal prosthetic part with respect to the element forreceiving.
 18. The prosthesis according to claim 1, wherein the levercomprises two lever parts, the lever parts being displaceably fitted toeach other.
 19. The prosthesis according to claim 18, wherein the leverparts are pivotally fitted to each other, and the pivot axis of thelever parts align with the pivot axis of the lever.
 20. The prosthesisaccording to claim 1, wherein the prosthesis is a prosthesis for a lowerlimb, the support part is for receiving a thigh stump or a thigh shaft,the pivot link forms a knee joint, and the distal prosthesis device is ashank part.